The present invention relates to the field of dental implants; more specifically, to an interface between a dental implant which is drilled and permanently fixed into the mandibular or maxillary bone and, a removable device inserted into the mouth by the end-user, such as, but not limited to dentures. The interface is known as an abutment in the field of dentistry, and will be referred to as the “invention” herein. Likewise, the removable device will be referred to as “prosthesis.”
Dental implants can be screw-like. Conventional two-piece implants comprise a cone-tip externally threaded at the distal or lower end, and a multi-position interface, such as a hexagonal socket head, at the proximal or upper end. Additionally, the proximal end is internally tapped into and below the hexagon socket. Alternatively, some dental implants may have a protruding feature such as a hexagon or other pattern at its proximal end. All features described thus far are concentric about a single vertical axis.
A hole is bored through the gums into the mandible or maxilla jawbone) by a dental surgeon. The dental implant is then fixed in place with implant specific tools thereby eliminating all degrees of freedom of movement. In most cases, the patient's teeth do not align on the same vertical axis as the dental implant. Consequently, an abutment is used to adapt between the implant's vertical axis and that of the prosthesis. The abutment should correct the angular misalignment between the two vertical axes as described above, and in some cases, it may account for translational misalignment.
A replica mold of the patient's mouth is created to facilitate design of the prosthesis in a laboratory environment. Adjustments must then be made when the prosthesis is installed into the patients' mouth in the dental office. Conventional abutments provide freedom of rotation about one or more axes. The dental surgeon fits the prosthesis to the implant via movement of the abutment to the desired position. The abutment is then fixed in place by way of a lock mechanism.
Anatomy of the human mouth varies widely between different individuals. Similarly, each manufacturer produces a unique variation to the prosthesis and implant design. An ideal abutment not only maximizes positional settings, but can accommodate a variety of prostheses and implants with minimal modification.
Numerous abutment designs describe multi-member assemblies in which the first or upper member mates with the prosthesis and is offset at an angle relative to the vertical axis thereby compensating for angular displacement between prosthesis and implant. The second or lower member mates with the dental implant and may rotate in a discrete number of orientations about the implant's vertical axis. In most cases, six orientations—every 60 degrees—are made available whereby a hexagon extrusion on the second member fits into a hexagon socket on the dental implant.
The patents herein are incorporated by reference in their entirety for all purposes. U.S. Pat. No. 6,299,447 issued to Zuest et al, U.S. Pat. No. 5,350,302 issued to Marlin, U.S. Pat. No. 5,195,891 issued to Sulc, and U.S. Pat. No. 4,988,297 issued to Lazarra et al, illustrate designs in which the upper member possesses a fixed offset angle. If the specific angle is unsuitable for the patient, the member may be exchanged for a matching member with a different offset angle.
Alternatively, abutment designs such as U.S. Pat. No. 7,214,063 issued to Cohen, U.S. Pat. No. 6,500,003 issued to Nichinormi, U.S. Pat. No. 5,073,110 issued to Barbone and U.S. Pat. No. 5,071,350 issued to Niznick, employ a spherical or ball-and-socket joint which provides greater flexibility in positioning. These offer freedom of rotation about all three axes: yaw, pitch and roll. The ideal orientation is obtained by unconstrained manipulation of the sphere which is then locked in place. Similarly, U.S. Pat. No. 4,823,601 issued to Linden engages a spherical unit set into a conical receptor.
All abutments disclosed herein are uniformly coupled to the prostheses whereby an extension of the prosthesis inserts into a hollow cylindrical or conical receptor on the proximal or upper aspect of the abutment.